Spring-suspension and steerablewheel assembly for straddle trucks



Feb. 18, 1947; w BARR 2,415,928

SPRING-SUSPENSION AND STEERABLE WHEEL ASSEMBLY FOR STRADDLE TRUCKS Filed March '7, 1945 III/ll.

. INVENTOR.

Patented Feb. 18, 1947 srnrNG-sUsPE sIoN AND VSTEERABLE- WHEEL ASSEMBLY FOR: STRADDILE T-RUGKS ;Walter A. Barr, Orange Tush, 1nd,,assignon to i The Boss Carrier Company, Benton Harbor,

"'Michl, a; corporation of Michigan Application March 7, 1945; Seriali'No.'S581,421

3 Claims; 1.

The-presentinventionpertains to certain structural advantages: and functional betterments in the spring-suspension and steering-means of trucks and more particularly, but not necessarily exclusively, in straddle-trucks, such as those used ,inyt'he transportation of lumber and other loads and-known in the trade as straddle-trucks becausethey straddle their load.

"Q e object of this invention is to provide increased'ease of steering the truck because the total load of the carrier is supported on ballbearings; the sidethrusts from the steering links and wheels being carried on the same bearings.

"Anotheraim of the invention is to provide a construction permitting approximately 360 of steer-ing rotation of the carrying-wheels without interference from spring supports.

Af-urthe'r pur ose of the invention is to supply a structure of this type wherein the supporting spring is completely-assembled within the fork and can,. therefore,..be packed-V in grease or oil and be protected'efficiently from corrosion and dirt and at the same time be thoroughly lubricated.

Moreover; the new construction the operators vision is not obscured by outside spring mechanism, asupplemental object of the inven tion being to supply a structure which eliminates a considerable number of parts heretofore believed to be necessary, thereby-providing a much simp1er;'c1eaner design in which the elements coact and cooperate with one-another in a satisfactory and efiicient manner to maintain the parts properly in place and to permit the construction to operate efiectively and efficiently,

To enable those skilled in this art to understand a present preferred embodiment of the invention accomplishing the above-indicated objects of the invention, such a construction has been illustrated in the accompanying drawing, forming a part of this specification, and to which reference should be had in connection with the following detailed description, it being borne in mind that like parts of the structure have been supplied with the same reference characters in both of the views presented in the drawing.

In this drawing:

Figure l is a partial elevation of one of the corner constructions of the straddle-truck which supports its load and also constitutes steeringmechanism for one corner of the truck, the sprocket-wheel and chain drive for the corresponding carrying-wheel being shown fragmentarily. and

Figure 2 is an enlarged, fragmentary, central,

verticalsection through a" portion only. oft-such structure.

Referring to this drawing; it will. be noted-that the appliance includes a round fork-sleeve lli,

constituting a corner casting of theirame-of the truck,- on which a corner" portion of-thetruck loadds'imposed-the lower open end of such sleeve beingv equipped; partially internally and partly externally, with a 'demount-able bearing [-2 slidingly' accommodating an'i-nner fork-tube l 3 longitudinally slotted along itstWosidEs 'inrre ri ter at M M; the otherwiseopentop :of the fork-sleeve M :being providedwith anrannularcover 'l5-de mountablyfixed to the top of--the sleeve-by a suitable plurality of bolts 16, l'GgQthBtllbG t3. extending up' out of the sleeve through a-central apertur'eofcorresponding size in the-cover, as is cleiarlyil-lustrated'.

T-ne lower end of tube H3 is appropriately mountedcon, andifixedly'secured to, the carryingwheel'assembly I15, 2! many approved manner, as by bolts 18 and welding, so thatwhen the tube is turned in the fork-sleeve by appropriate steering-mechanism:including anarm 20 formingpart of the' closure 1-0 fixed in :anysuitable'mam ner to'the topofx-ltube I3; "the: wheel 2| and. its steering means, designated as 'a;-whole by [includ'ing its'sprocketewheeland chain connection M9 illustrated fragment-arily, will be' turnedzzcon respondingly to perform its-portion of thesteering action of the vehicle.

A coiled;loadrsupporting; spring 22 isuhoused within the upright tube I3 and bears at its lower end on the wheel-assembly ll, 2|, by which it is supported, a round bearing-member 23, of substantially the same size as the interior of the tube l3 in which it is located, pressing against the top end of spring 22 and having a downwardly-extended, round projection 24 protruding into the interior of the spring, as is clearly portrayed, such part 23 having a round horizontal opening 25 therethrough occupied by a cylindrical pin 26 of a length substantially the same as that of the interior diameter of the sleeve II and extending outwardly in opposite directions through the tube slots 14, I4 with its projecting ends occupying opposite registered apertures 21, 21 in a round bearing-collar 28 between the tube and sleeve and having an internal diameter approximately the same as the external diameter of the tube l3 and having an outer diameter about the same as the inner diameter of the sleeve ll.

Between the bearing-collar 28 and the undersurface of the sleeve-cover I5 is a circular ballbearing including an annular row of balls 29 becircular marginal rib 33 overlapping the outer edge of the part 32, as shown.

Obviously as the load on the fork-sleeve H- varies, the spring'22 will be compressed downwardly more or less, the fork-assembly outside of the tube, by reason of its sliding connection with the tube, occupying difierent positions lengthwise the latter depending upon the amount of its load, such relative longitudinal displacement of the parts being permitted by reason of the presence of the slots l4, M in the tube which allow the pin 26 to change its elevation in the tube.

Regardless of the load acting on the spring, the turning of the tube by the steering-mechanism 20 can be readily accomplished for steering the carrying-wheel, the tube being oscillatory in the two bearings I2 and 29. r Although not illustrated in the drawing, th fork-sleeve ll may be completely filled with any suitable lubricant, solid if preferred, for efficient lubrication of the moving parts, all of which are effectively housed and protected in the sleeve,

An'dndemtanding of this construction and its mode of operation will readily convey to one skilled in the art the manner of attaining the several objects of the invention hereinabove set forth and in this connection it should be borne in mind that the invention, as defined hereinafter, isnot necessarily limited and restricted to the exact and precise details of structure and that these may be modified within reasonable limits without departure from the heart and essence of the invention, and without the loss or sacrifice of any-of its material benefits and advantages.

Iclaim:

1-. In a straddle-truck spring-suspension including a fork-sleeve on, and supporting its portion of, the truck-frame, a fork-tube rotatable and slidable in said sleeve, a spring in said tube bearing-at its lower end on a carrying-wheel assembly, means to impose the supported load on the upper end of the spring, and means to turn said tube in said sleeve to steer said wheel, the novel-improvement in an upper bearing of said 4 tube including in combination a bearing-collar between said fork-sleeve and said fork-tube and oppositely apertured in register with opposite longitudinal slots through said fork-tube, a bearingmember inside of said tube with an opening therethroughin' register with said tube-slots and bearing on the upper end of said spring, a crosspin occupying the apertures of said bearing-collar, the slots of said tube and the opening through the bearing member, a cover on said fork-sleeve centrally apertured to accommodate said forktube and covering the annular space between said fork-sleeve and fork-tube, and a ball-bearing between said bearing-collar and said cover, whereby said tube ma turn in said sleeve for steering and the load on said fork-sleeve is imposed on said spring through said ball-bearing, bearingcollar, cross-pin and bearing-member, these parts being free to move lengthwise of the tube by reason of the slots in the latter.

2. The novel improvement as set forth in claim 1, in which said ball-bearing has a lower inner race around said tube and an upper outer race against the under-surface of said cover and the inner surface of said fork-sleeve.

3. The novel improvement set forth in claim 1-, in which said ball-bearing includes an upper outer race bearing against the under surface of said cover and the inner surface of said forksleeve, and a lower inner race around said forktube and of approximately the same inner diameter as the outer diameter of the tube onwhich it bears, said lower inner race being also in contact with the upper face of the bearing-collar, the latter having an upstanding circular marginal rib overlapping the outer edge of the lower inner race.

WALTER A. BARR.

, REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

